https://issues.dlang.org/show_bug.cgi?id=18600
--- Comment #2 from Jon Degenhardt <jrdemail2000-dl...@yahoo.com> --- Phobos PR 6268 was included in LDC 1.10.0-beta1. For this release the standard benchmark I used for the TSV Utilities improved as follows: LDC 1.7.0 (before regression): 8.37 seconds LDC 1.8.0 (after regression): 10.01 seconds LDC 1.9.0 (first fixes): 9.44 seconds LDC 1.10.0-beta1 (Phobos PR 6268): 5.85 seconds First fixes: Phobos PR 5981, DMD PR 7599 The benchmark test used reads a TSV file line-by-line and checks individual fields for regex matches. A significant amount of processing time is IO, so the percentage gain on the regex portion is higher than the overall gain. The overall gain from LDC 1.7.0 is 30%. Test was run on MacOS, MacMini with 16GB RAM, SSD drives. The file used was 2.7GB, 14 million lines. Test info can be found here: https://github.com/eBay/tsv-utils-dlang/blob/master/docs/ComparativeBenchmarks2018.md Great result! --